Last year there were many disasters around the world that were not predicted. But the one that was expected to happen - the millennium bug - did not. Or at least not yet.

Yesterday the City breathed a collective sigh of relief when dealings reopened without serious problems after the new year closure period. Robin Guenier, chairman of Taskforce 2000, however, argues that bug-related problems are spread over a long period and that 65% have yet to surface. He may be proved right. But to most business people, the worst of the scary scenarios is over. The debate now is about whether the $400bn to $500bn spent teaching computers to tell the time properly was brilliantly successful or a complete waste of money that could have been better spent on building hospitals and schools.

Questions are being asked that will keep business schools occupied for years. For instance: how is it that countries spending very little on bug prevention (ranging from Italy in the developed world to most countries in the third world) appear so far to have escaped serious effects? Of course, just because governments (as in Italy) may have spent very little, it does not follow that companies, with more to lose, will have done the same. Even if there was not a problem in the first place - a difficult hypothesis to prove - the episode has led to a global refurbishment of computers which ought to make industry more efficient (besides helping to fuel the stock market boom). That does not necessarily justify the expense incurred - but maybe the business school students should look at that too. If the total bill is $500bn, that amounts to $83 for every man, woman and child in the world, including the vast majority of people in China, India and Africa who do not have computers. An audit is clearly needed. But even that will not stop the debate. It says something about the millennium spirit that we seem as worried about disasters avoided as disasters experienced.